EI05119 - Power Steering Gear Leak, Moan, Groan or Whine Noise (Diagnose and Repair as Necessary)

This bulletin is being revised to provide additional leak and noise diagnosis information. Please discard Corporate Bulletin Number 05-02-32-007C (Section 02 -- Steering).

Some customers may comment on a power steering gear leak or that the gear appears to be leaking. Additionally, the customer may come into the dealership indicating they were told by an aftermarket service facility that the steering gear was leaking because the power steering reservoir was low on fluid and the gear showed an oil residue.

Some customers may also comment on a power steering noise during steering maneuvers or while driving.

Inspect and diagnose the power steering system before any repairs are attempted using the procedure listed below.

Important: Because the power steering reservoir on 3800 V6-equipped vehicles is located behind and below the rear cylinder head, the fluid level may not be getting checked and/or topped off similar to other vehicles which have a reservoir that is located on the upper portion of the engine. This condition could be more prevalent with vehicles serviced at non-GM dealerships.

1. Determine if the power steering system is full of oil. Adjust the fluid in the reservoir to the proper level.

The lower fluid level could be the result of a variation in the original system fill. Plus, over time and mileage, the system purges any remaining air. Additionally, as the hoses expand and contract, the fluid level may drop as measured within the reservoir. Don't assume there is an external fluid leak just because the fluid level in the reservoir is down to the Add mark.

2. Restart the engine and see if the noise goes away after turning the steering wheel lock to lock a few times. This will correct most, if not all, the vehicles with a noise condition.
3. If the customer was told their was a power steering fluid leak by an aftermarket service facility because the power steering reservoir needed fluid and they saw oil residue on the power steering gear, then carefully inspect the gear and surrounding area for oil residue. Below are some causes as to why oil residue may be present.

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Oil residue on the body of the steering gear usually on the pinion area (left side) of the gear or on the convoluted boots. This condition could be caused by a small amount of oil that can drip out when the shipping plugs are removed from the gear, just prior to the installation of the P/S pressure and return lines being connected at the assembly plants.Gears should not be replaced for this condition.

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Oil residue on or near the pinion adjuster nut plug. During the gear assembly process the supplier uses grease to lubricate the pinion adjuster plug threads. In cases where a lot of grease was used on the adjuster plug threads, some grease can ooze out around the threads and when mixed with moisture and road grime, it can appear as though the plug is leaking. In some cases the heat generated from the exhaust system will start to liquefy some of the grease and cause it to run. Gears should not be replaced for this condition.

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Oil residue inside the convoluted boots. When the steering gear is assembled into the housing, grease is applied to the gear teeth. In some cases, if there is a lot of grease used, it will squeeze out of the gear teeth, soften and run down and collect in the bottom of the convolutes. This may have the appearance of a thick oil, especially in hot climates. Some technicians have seen this liquefied grease and thought is was power steering fluid. Gears should not be replaced for this condition.

4. If the customer indicates that they have seen what they think was a leak, resembling oil residue, on their garage floor or driveway, or the technician sees drops of oil leaking, carefully inspect the power steering hydraulic system. The inspection should be performed while the engine is running and the steering wheel is rotated from lock to lock. If a leak is observed, then repair the source of the leak.
5. If the noise is not the result of low power steering fluid, provide a complete description of when the noise happens and what type of noise it is; i.e. squeal, pop, clunk, tick, continuous rubbing, etc. If it is a pop or clunk noise, make sure you inspect the convoluted boots to determine if the inner tie rod is rubbing the boots. Replace the boot or boots only for this condition. If the noise is a clunk or pop noise and it's not the inner tie rod rubbing the convoluted boots, make sure to inspect the intermediate shaft for the slip stick condition. This should be done prior to replacing any steering gears.

Important : If amber/yellow tinted glasses and the "pen light" style of black light are used, the lithium in the grease will show up in greenish/yellow similar to the greenish/yellow dye used by many dealerships to test for leaks. Always use the black light recommended by GM Tools and clear glasses to inspect for dye in fluid leaks.

6. If the source of the leak cannot be found by visual inspection, add dye, P/N 88861206 (in Canada, use P/N 88861259), and inspect the system using Black Light (J 28428-E or J 42220).

The number of vehicles that will require a complete inspection using dye will be minimal based on the inspection of numerous steering gears returned for testing where the complaint was fluid leak and no leaks could be reproduced.

Important: If a steering gear is replaced because a leak was discovered using the dye test method, make sure the repair order has a description of where the leak was discovered. If the steering gear is replaced for a noise concern, make sure a complete description of the diagnosis appears on the repair order as described in Step 5 above. Steering gears replaced under warranty will continue to be on parts return and regional feedbacks will be processed on any gears which the customer complaint cannot be verified. Over 90% of all steering gears inspected have little or no explanation of the condition, the technician's diagnosis or reason for replacing the gears and/or did not have any indication that dye was used to find a leak.